This invention relates to nickel-base alloys particularly suitable for high temperature molten glass environments.
In one of its more specific aspects, the invention relates to articles manufactured from the alloys, particularly articles made by casting for use in molten glass processing.
In certain glass applications, there is a need for alloys which possess high rupture strength and high oxidation resistance at high temperatures. Among such applications are those involved, for example, in the glass fiber industry, where filaments are produced by flowing molten glass through the peripheral walls of a chamber capable of rotating at high speeds. The chamber is known as a Spinner Disc. The filaments are formed through openings in the wall due to the centrifugal action to which the molten material is subjected when rotating the Spinner Disc.
The Discs are usually operated when spinning glass fibers at temperatures of about 1900.degree. F. and rotational speeds of about 1400 RPM. Under these conditions, the alloy of this invention has been found to possess superior stress-rupture and creep properties and superior resistance to the molten glass environment to which it is subjected. This apparatus is described more particularly in U.S. Pat. No. 3,190,736 which issued on June 22, 1965, to Stanley Benner for a "Rotor For the Forming of Glass Filaments." This reference describes in detail the construction of a spinner disc and the manner of its use.
U.S. Pat. No. 3,881,918 which issued on May 6, 1975, to Darryl J. Costin and James B. Ford for a "Cobalt-Base Superalloy" contains an interesting and informative discussion of nickel and cobalt-base superalloys which have been found to be useful in high temperature corrosive and oxidizing environments. This reference discusses applications in jet engines and also in the chemical industries for the particular alloys discussed therein which are useful chiefly at temperatures of at least 2,000.degree. F. Although the particular compositions in this reference are substantially different from those in the present invention, the discussion of the alloying procedures, properties and testing is of sufficient value that this particular patent is incorporated herein by reference in its entirety.
It is an object of this invention to provide a nickel-chrome base alloy having superior stress-rupture and creep properties, and an alloy which can be melted and cast, and which is particularly resistant to corrosion by molten glass.